Structural and surface potential characterization of annealed HfO ₂ and (HfO ₂) _x(SiO ₂) _1-x films

The structural and surface potential characterization of annealed hafnium oxide and hafnium silicate films with high temperature anneals and their relationship to morphological changes was analyzed. The as-grown, amorphous 3 nm thick HfO 2 and 2.2 nm thick Hf 0.78Si 0.22O 2 layers were deposited ex situ on Si(100). A noncontact atomic force microscope was used to image the topography, contact potential difference (CPD) and differential capacitance. It was shown that CPD variations were about a factor of 2 larger than for SiO 2 gate oxides.